Electronically scanned antennas for micro-millimeter-wave (MMW), or W-band, typically above 35 Ghz, applications are traditionally expensive to build and very few have been developed. The ones that have been demonstrated are generally implemented as a microstrip patch or slot array. The packaging constraints and the costs associated with the electronics of these conventional approaches make a fully populated discrete array impractical. Additionally, these designs require many levels of lossy feed networks, and the tolerance is so tight that the production cost can be relatively high. Aperture efficiency is always an issue at W-band.